Lifting Weights Burns Fat

Why Weight Lifting Is Better Than Cardio For Fat Loss

Weightlifting is totally better for fat loss than cardio, because broscience.

In this case I’m going to agree with the bros; even though I’m a Boston Marathon qualifier, there is a compelling argument why weightlifting is better for lowering body fat.

Hang on; it’s complicated.

Muscle Mass and MetabolismOne book I recommend is Strength Training for Fat Loss by Nick Tuminello. It provides detailed instruction on lifting weights in a manner that is metabolically costly. That means you burn a lot of calories doing it, plus you build muscle. Awesome.

It’s the “build muscle” part where the author perpetuates a myth, however. In an otherwise great book, Nick says that a pound of muscle burns an extra 30 calories per day while at rest. His source for this is another excellent book: The M.A.X. Muscle Plan by Brad Schoenfeld. (I interviewed Nick and Brad for this piece on weight machines; they’re two of the wisest men in weightlifting.)

Brad doesn’t offer an original source for the metabolic rate of muscle at rest. Indeed, I’ve never seen any scientific backing for the claim. It’s apocryphal, and I busted it a while back for the Los Angeles Times, interviewing a metabolism researcher and looking at multiple scholarly sources. The reality is that muscle only burns about 6 calories per pound per day while at rest, and if you’re dropping a lot of fat, you also need to account that a pound of fat burns about 2 calories per pound/day at rest.

Hypothetically, if you gain 20 pounds of muscle and lose 60 pounds of fat, you break even in terms of effect on resting metabolism. This doesn’t even take into account that you’re 40 pounds lighter overall for every step you take and every flight of stairs you climb, meaning fewer calories burned each day.

The Caloric Cost of Cardio vs. LiftingEven though Tuminello’s program is high intensity, it’s still not going to equal a hard cardio workout. Essentials of Strength Training and Conditioning puts “vigorous” weightlifting at 6 METs (six times resting metabolism). Compare this to a fast-ish run of 7.5 mph, and the caloric burn rate is more than double at 12.5 METs. As an example, a guy who weighs 220 will burn about 100 calories per hour on the couch, 600 calories per hour at vigorous lifting, and 1,250 calories per hour running at 7.5mph.

Nick’s program is probably even higher than 6 METs, because he uses a circuit that makes it “extra vigorous,” but as someone who is both a lifter and a runner, I can’t see this intensity matching the caloric burn rate of a hard run. Oh, and never mind about caloric “after burn” for cardio or weights. It’s been way overblown.

It's worth mentioning the broscience articles that say cardio slows your overall metabolism. Duh. Any exercise will do that. That’s what getting in shape means. Fine-tuning your body into a higher performance machine, via either weights or cardio, doesn’t turn it into a “fat incinerating blast furnace” while at rest. It makes it more efficient, and added muscle mass doesn’t make much of a dent in this.

There is more to this story, however.

Comparing Via Clinical StudyA 2012 study of 119 overweight or obese people published in the Journal of Applied Physiology randomized them into three groups: Resistance training alone (RT), aerobic training alone (AT), or both.

Check out this graph. RT is on the left, AT in the middle, and both on the right: Source

Obviously, both is the way to go for fat loss, but it’s also worth noting that, for this study, doing both took twice as long as just RT or AT. Not everyone has that kind of time or motivation.